Spring joints are especially suitable for providing a pivotable connection of two bodies since they function with a very high reproducibility. Spring joints are known wherein several leaf springs are mounted in the interior of two spring action is provided essentially in only one plane and they have a negligible spring action in the direction perpendicular to this plane. For this reason, especially spring joints or spring bearings having a predirected force can be made. Such spring joints permit the radial/axial support of bodies or components in an essentially precise friction-free, play-free, low-hysteresis, wear-free and dry manner with the bodies requiring a limited freedom of rotation and which bodies must be driven under extreme environmental conditions (dirt, cold, heat, vacuum, vibration, shock).
These spring joints find a wide application as supports in sensors which, for example, measure displacements, angles, torques, forces and the like and are built into measuring devices, machines, microscales, gyroscope devices (here especially for rate gyros and dynamically matched gyroscopes as frame or cardanic bearings). Spring joints of the kind described above are disclosed in German Patents 2,525,530 and 2,653,427 and U.S. Pat. No. 4,310,303.
Problems occur as a rule when dimensioning the spring joints in response to requirements as to load-carrying capacity (as high as possible) and rotation spring constants or directing force, return force (as low as possible).
The deflection is always a compromise since handling and transport requirements (for flying bodies and the like and such as the starting thereof) usually require a dimensioning for load-carrying capacity which lies well above the actual operating conditions.
However, the foregoing leads to undesired stiff bearings having associated therewith high return forces, reduced rotational angle freedom, greater hysteresis and the like.
For most applications, it is permissible and important that the bearings can be operated without being destroyed for the time interval of a time-limited load lying well above the normal operating conditions with the operation of the bearing being possibly limited in function (such as not being free of friction) if the full function is again provided thereafter or the function is only slightly affected.